Colossal Magnetoresistance in Ti Lightly Doped Cr₂Se₃ Single Crystals with a Layered Structure

Abstract

Stoichiometric Cr 2 Se 3 single crystals are particular layer-structured antiferromagnets, which possess a noncollinear spin configuration, weak ferromagnetic moments, moderate magnetoresistance (MR ∼14.3%), and poor metallic conductivity below the antiferromagnetic phase transition. Here, we report an interesting >16 000% colossal magnetoresistance (CMR) effect in Ti (1.5 atomic percent) lightly doped Cr 2 Se 3 single crystals. Such a CMR is approximately 1143 times larger than that of the stoichiometric Cr 2 Se 3 crystals and is rarely observed in layered antiferromagnets and is attributed to the frustrated spin configuration. Moreover, the Ti doping not only dramatically changes the electronic conductivity of the Cr 2 Se 3 crystal from a bad metal to a semiconductor with a gap of ∼15 meV but also induces a change in the magnetic anisotropy of the Cr 2 Se 3 crystal from strong out-of-plane to weak inplane. Further, magnetotransport measurements reveal that the low-field MR scales with the square of the reduced magnetization, which is a signature of CMR materials. The layered Ti:Cr 2 Se 3 with the CMR effect could be used as two-dimensional (2D) heterostructure building blocks to provide colossal negative MR in spintronic devices.

Spin Reorientation Transition and Negative Magnetoresistance in Ferromagnetic NdCrSb3 Single Crystals

“…The negative MR along the a axis is approximately 10% at 10 K with 2 T, while MR along the b -direction is about 5%. The negative MR has also been reported in Cr 2 Se 3 [ 16 ] and Ti-doped Cr 2 Se 3 [ 17 ] crystals due to the similar reasons. MR beyond the spin reorientation temperature range for both two directions are positive, further supports the high disorder states in SR region.…”

Coexistence of logarithmic and SdH quantum oscillations in ferromagnetic Cr-doped tellurium single crystals

“…As shown in figures 1(g) and (h), the Cr dopant is uniformly distributed within the cross-sectional area of the crystal, with an overall Cr concentration of ∼7.7 atom% (figure 1(i)), which is 10% larger than the nominal doping level of 7 atom%. The slight off-stoichiometric effect was also reported in other single crystals that were grown via vapor-transport-based single-crystal growth methods [21,22]. Figure 1(j) shows a typical atomically resolved HRTEM image of a Cr:Te crystal.…”

Optimizing Electron Spin‐Polarized States of MoSe2/Cr2Se3 Heterojunction‐Embedded Carbon Nanospheres for Superior Sodium/Potassium‐Ion Battery Performances

“…The internal electric field present in the heterogeneous interface facilitates the transfer of electrons from MoSe 2 to Cr 2 Se 3 . [46] In combination with the strong adsorption capacity toward sodium/potassium, improving the kinetics of ion and electron transfer. In Figure 4b, the yellow atom is Na atom in MoSe 2 /Cr 2 Se 3 heterojunctions.…”